Delicious Apples
Time Limit: 5000/3000 MS (Java/Others) Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 321 Accepted Submission(s): 95
Problem Description
There are 
apple
trees planted along a cyclic road, which is 
metres
long. Your storehouse is built at position 
on
that cyclic road.
The
th
tree is planted at position 

,
clockwise from position 
.
There are 

delicious
apple(s) on the 
th
tree.
You only have a basket which can contain at most
apple(s).
You are to start from your storehouse, pick all the apples and carry them back to your storehouse using your basket. What is your minimum distance travelled?














































There are less than 20 huge testcases, and less than 500 small testcases.



The







You only have a basket which can contain at most















































There are less than 20 huge testcases, and less than 500 small testcases.
Input
First line: 
,
the number of testcases.
Then
testcases
follow. In each testcase:
First line contains three integers,




.
Next
lines,
each line contains 




.

Then

First line contains three integers,





Next






Output
Output total distance in a line for each testcase.
Sample Input
2 10 3 2 2 2 8 2 5 1 10 4 1 2 2 8 2 5 1 0 10000
Sample Output
18 26
解题思路:
注意到,最多仅仅有一次会绕整个圈走一次。因此,先贪心的处理左半环和右半环。然后枚举绕整圈的时候从左側摘得苹果和从右側摘得苹果的数目。
#include <iostream> #include <cstring> #include <cstdio> #include <cstdlib> #include <vector> #include <queue> #include <stack> #include <cmath> #include <algorithm> #define LL long long using namespace std; const int MAXN = 100000 + 10; int L, N, K; LL x[MAXN]; LL ld[MAXN], rd[MAXN]; vector<LL>l, r; int main() { int T; scanf("%d", &T); while(T--) { scanf("%d%d%d", &L, &N, &K); l.clear(); r.clear(); int pos, num, m = 0; for(int i=1;i<=N;i++) { scanf("%d%d", &pos, &num); for(int i=1;i<=num;i++) x[++m] = (LL)pos; } for(int i=1;i<=m;i++) { if(2 * x[i] < L) l.push_back(x[i]); else r.push_back(L - x[i]); } sort(l.begin(), l.end()); sort(r.begin(), r.end()); int lsz = l.size(), rsz = r.size(); memset(ld, 0, sizeof(ld)); memset(rd, 0, sizeof(rd)); for(int i=0;i<lsz;i++) ld[i + 1] = (i + 1 <= K ? l[i] : ld[i + 1 - K] + l[i]); for(int i=0;i<rsz;i++) rd[i + 1] = (i + 1 <= K ? r[i] : rd[i + 1 - K] + r[i]); LL ans = (ld[lsz] + rd[rsz]) * 2; for(int i=0;i<=lsz&&i<=K;i++) { int p1 = lsz - i; int p2 = max(0, rsz-(K-i)); ans = min(ans, 2*(ld[p1] + rd[p2]) + L); } cout << ans << endl; } return 0; }